A Study of Cardiovascular Events iN Diabetes - A Randomized 2x2 Factorial Study of Aspirin Versus Placebo, and of Omega-3 Fatty Acid Supplementation Versus Placebo, for Primary Prevention of Cardiovascular Events in People With Diabetes

The role of antiplatelet therapy (chiefly aspirin) for the secondary prevention of heart attacks and strokes is firmly established for many high-risk people with diagnosed arterial disease, and the proportional reductions in these cardiovascular events appear to be about one quarter, whether or not such patients have diabetes. But, most younger and middle-aged people with diabetes do not have manifest arterial disease - although they are still at significant cardiovascular risk - and yet few trials have tested aspirin in such individuals. As a result, there is substantial uncertainty about the role of aspirin for the prevention of heart attacks and strokes among apparently healthy people with diabetes, and only a small minority receives it.

There is consistent evidence from observational studies of lower rates of cardiovascular disease (particularly cardiac and sudden death) in people with higher intakes, or higher blood levels, of fish oils (omega-3 fatty acids). Trials in people who have survived a heart attack have shown modest, but potentially worthwhile, reductions in coronary events.

If ASCEND can reliably demonstrate that aspirin and/or fish oils safely reduce the risk of cardiovascular events and deaths in people with diabetes who do not have pre-existing arterial disease, then this would be relevant to some tens of millions of people world-wide (who are currently not receiving such therapy) and might save tens of thousands of lives each year.

The initial results (published 2018) showed that aspirin prevented serious vascular events in patients with diabetes who did not already have cardiovascular disease, but it caused almost as many major bleeds and there was no effect on cancers. There was no significant difference in the risk of serious vascular events between those who were assigned to receive n-3 fatty acid supplementation and those who were assigned to receive placebo.

ASCEND will be conducting long-term follow-up for 20-years beyond the scheduled treatment period (which ended in 2017). We will collect relevant data from UK central health registries. This will be used to assess whether the balance of benefits versus hazards of aspirin observed within the main trial, relating to major vascular events such as heart attack or stroke, continue long-term or whether additional benefits emerge during longer-term follow-up.